Improvement in depilating hides and preserving wood



UNITED STATES PATEELQEFFQE- JOHN E. SIEBEL, OF CHICAGO, ILLINOIS.

Specification forming part of Letters Patent No. 116,638, dated July 4, 1871.

To all whom it may concern:

Be it known that I, JOHN E. SIEBEL, of Ohicago, in the county of Cook and State of Illinois, have invented certain Improvements in the U tilizationof liefuse Gas-Lillie, of which the following is a specification:

The bluish-green mass which is produced in the purification of illuminating-gas, and which is considered a very obnoxious refuse by gas- 7 makers, I term refuse gas-lime, a name by which this substance is generally known. This substance consists of sulphide and sulphydrate of calcium, and small quantities of the lime-salts of carbonic and subsulphurous acid. The two first-named in gredientsviz., sulphide of calcium and sulphydrate of calcium1'ender this refuse applicable for the purposes specified herein.

Mixed with water this refuse forms a mixture which, on account of its containing sulphydrate of calcium, I use as a cheap and effective depil atory, especially useful for tanneries, to free the hides to be tanned from thehair. For this purpose the gas-lime (as soon as possible after it leaves the refining apparatus of the g2 s-factory) is mixed with water to form a thick liquid or paste, in which the hides are innnersed until the hair becomes loose and can be removed by ablunt knife.

Extracted by water, the refuse gaslime produces a solution which (especially when made from fresh refuse) contains large quantities of sulphide and sulphydrate of calcium. This solution I use in connection with a solution of either sulphate ofzinc, or ferrous sulphate, or ferric sulphate, for the preservation and impregnation of .hnnber in the following manner: After the wood is freed from sap, and its pores opened by steamanother impregnation is made into the wood by the solution obtained by treating gas-lime refuse with water, say in the proportion of one pound of gas-lime refuse to one gallon of water, more or less. If in the first impregnation ferrous or ferric sulphate were used, the second impregnation will produce within the pores of the wood insoluble deposits of sulphate of lime and black sulphide of iron; but if sulphate of zinc be used in the first injection the deposits formed will be sulphate of lime and sulphide of zinc, which are also both insoluble in water, but of a white color. The use of zinc-sulphate in this process is therefore rectnnmemlable in case the wood to be preserved not desired to be stained or colored. If desired, the first impregnation of the wood may be made with the watery extract of the gaslime refuse, and the second impregnation with a solution of any one of the above-mentioned three sulphates.

The serious objections which exist against an older process used occasionally for preserving wood, and which. process consists in the successive impregnation of ferrous sulphate and burned lime in watery solution, cannot be quoted against my process. The objection referred to is the very small solubility of burned lime in water, which allows but an almost insignificant portion. to enter the wood, while the sulphide and sulphydrate of calcium, which are the essential agents brought to bear in my process, are very soluble in water, and can therefore be imparted to the wood in any desired quantity.

W hat I claim is 1. The use of refuse gas-lime as a depilatory, especially for the use of tanneries, substantially as set forth.

2. The use of refuse gas-lime in connection with either one of the three following substances, via: sulphate of zinc, ferrous sulphate, or ferric sulphate, for the impregnation and preservation of wood, substantially as set forth.

JOHN E. SIEBEL.

Vitnesses G. PROEBSING, WM. GLA'ENZER. 

